JPS624210B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blow molding mold, and relates to a pair of split molds 2, 2 for blow molding that can be freely mated and separated through a gap 1.
The split mold 2 is disposed near the gap 1 so as to protrude freely toward the other split mold 2 on the outer surface of one of the split molds 2. A cutting blade 3 for cutting the resin leaked to the outer surface of the mold, a driving means 4 for driving the cutting blade 3, and the other split mold 2 formed by covering the surface of an elastic body 13 with a hard material 14.
This relates to a blow molding die comprising a blade support member 12 fixed to the outer surface of the hard material 14 so that the cutting edge 11 of the cutting blade 3 comes into contact with the surface of the hard material 14.

Conventionally, molded articles have been manufactured by blow molding as shown in FIGS. 1a to 1c. That is, a soft tubular parison 5 pressed from an extruder is placed in a pair of hollow molding molds 2, 2.
The mold is clamped with the mold 5, and air is blown into the parison 5 to obtain a molded product 6 having a hollow interior as shown in FIG. 1b. However, in this method, the molding resin flows between the split molds 2 and 2.
There was a problem in that the burr 7 leaked onto the outer surface of the mold 2, and the burr 7 had to be manually cut off after the molded product 6 was taken out from the split mold 2. In this manual process, the precision of the burr-finished surface is poor,
Moreover, the molded product 6 was still hot and the work was carried out at high temperatures, making it dangerous.

The present invention has been made in view of the above points, and provides a blow molding mold that eliminates the need to manually cut off burrs after molding by cutting burrs with a cutting blade attached to the mold immediately after molding. The purpose is to provide

The present invention will be explained in detail below with reference to Examples. As shown in FIG. 2, a pair of split molds 2, 2 for hollow molding are respectively attached to the inner surfaces of a pair of presses 8, 8 which can be driven to join and separate, and the pair of split molds 2, 2 have a gap of 1. The connection and separation can be driven freely through the . A recess 9 is formed in the split mold 2, and both split molds 2, 2
When the mold is clamped, a molding cavity 10 is formed here, and the molded product 6 is molded within this molding cavity 10. A driving means 4 such as a hydraulic cylinder is disposed on the side surface of one of the split molds 2, and a cutting blade 3 is attached to the driving means 4. This cutting blade 3
is slidably attached to the outer surface of the split mold 2 with its cutting edge 11 facing the gap 1 between the two split molds 2, 2, and is made to freely protrude into the gap 1 by driving the driving means 4. There is. The cutting edge 11 of the cutting blade 3 has a saw blade shape bent in a zigzag manner as shown in FIG. The cutting blade 3 is attached to the outer surface of the split mold 2, which is different from the split mold 2 to which the cutting blade 3 is attached, through the gap 1.
A blade receiving material 12 is arranged and fixed at a position facing the. As shown in FIG. 4, this blade receiving member 12 is formed by covering the surface of an elastic body 13 such as foamed urethane resin with a hard material 14 such as a stainless steel plate.

When performing blow molding with the blow molding mold having the above configuration, a soft tubular parison 5 made of synthetic resin is placed between the split molds 2 and 2, and the press 8 , 8 to tighten the parison 5 with the split molds 2, 2. At the same time, air is blown into the parison 5 to inflate it, and the split mold 2
is cooled to form a hollow molded product 6 as shown in FIG. A part of the resin leaks to the outer surface from the gap 1 between the split molds 2 and 2 when the molds are clamped, forming a burr 7, but the temperature of this burr 7 is sufficiently lowered and solidified. Afterwards, the driving means 4 is driven to project the cutting blade 3, and the burr 7 is cut by shearing between the cutting blade 3 and the opposing corner of the split die 2. At this time, by bending the cutting edge 11 of the cutting blade 3 into a saw blade shape, the burr 7 can be cut with lower pressure than a straight blade. Also, the cutting blade 3 after cutting the burr 7
The cutting edge 11 of the blade holder 12 will come into contact with the blade holder 12, but the impact of the cutting blade 3 can be buffered by the elasticity of the blade holder 12 and the blade edge 11 can be protected. As shown in c to c, the surface of the blade receiving material 12 is bent along the sawtooth-shaped cutting edge 11, and the gap 15 between the cutting edge 11 and the surface of the blade receiving material 12 can be completely eliminated. This allows the burr 7 to be completely cut off.

As described above, the present invention includes a pair of split molds for hollow molding that can be freely mated and separated through a gap, and a projecting part on the outer surface of one split mold near the gap toward the side of the other split mold. a cutting blade which is freely arranged and cuts resin leaked from the gap between the split molds to the outer surface of the split mold;
Since the cutting blade is equipped with a driving means for driving the cutting blade, the burr of the molded resin that has leaked from between the two split molds to the outside surface of the split mold through the gap and hardened is cut along the surface of the split mold with the cutting blade. It is possible to streamline the molding work even in large-scale blow molding, as there is no need to manually cut the burrs on the molded product after removing it from the split mold as in the past, and it can be done mechanically. This improves safety, and
The blade support material is formed by covering the surface of the elastic body with a hard material and is fixed to the outer surface of the other split mold so that the cutting edge of the cutting blade comes into contact with the surface of the hard material. When pressed against the hard material surface of the blade resting material, the surface of the blade resting material deforms elastically, and there is no gap between the cutting edge of the cutting blade and the surface of the blade resting material. The burr is completely cut between the cutting blade and the blade receiving material, improving the accuracy of the burr finished surface, improving the quality of the molded product, and reducing problems with mold accuracy. Moreover, after cutting the burr, the cutting edge of the cutting blade hits the blade support material with force, but the impact of the cutting blade can be absorbed by the elastic deformation of the blade support material, and the cutting blade This can prevent the cutting edge from being damaged in a short period of time.

[Brief explanation of the drawing]

Figures 1 a, b, and c are explanatory diagrams showing the conventional manufacturing method, respectively. Figure 2 is a sectional view of essential parts of an embodiment of the present invention, and Figures 3 a and b are enlarged sectional views of the same cutting blade. Figures 4a and 4b are front sectional views and side sectional views of the blade receiving material of another embodiment of the same as above, and Figures 5a, b, and c are the same as the above blade receiving material and cutting blade during cutting. It is a sectional view showing movement of. 1 is a gap, 2 is a split mold, 3 is a cutting blade, 4 is a driving means, 11 is a cutting edge, 12 is a blade receiving material, 13 is an elastic body, and 14 is a hard material.

Claims (1)

[Claims] 1 A pair of split molds for hollow molding that can be freely mated and separated through a gap, and a split mold that is disposed near the gap on the outer surface of one of the split molds so as to freely protrude toward the side of the other split mold. A cutting blade for cutting the resin leaked from the mold to the outer surface of the split mold through the gap, a driving means for driving the cutting blade, and the other split mold formed by coating the surface of an elastic body with a hard material. and a blade support member fixed to the outer surface of the blade so that the cutting edge of the cutting blade comes into contact with the surface of the hard material.